rock decoppering

captainsmitty · Feb 29, 2016

Ahoy there one and all. I have some rocks that I had used in a FISH ONLY tank from about 20 years ago (ya I have had tanks for over 50 years mostly fresh water).
I know i used some copper in the tank with these rocks. So my question is:
How to remove copper (if possible) from old rock work to use in a reef tank?
Thanks for your input and am interested in what you have to say.
Capt. Smitty

Adam Obenauf · Feb 29, 2016

Acid bath.

captainsmitty · Feb 29, 2016

and how would you go about doing an acid bath?

Reefing Madness · Feb 29, 2016

Throw the rock in a tub and run carbon in a mechanical filter until you don't test copper in the water.

cb684 · Feb 29, 2016

It might be a good idea to use cuprisorb or poly filter for a while. And I would only rely on tests that have the minimal detection limit similar to Triton (I do not know any other). As far as I know the detection limit of other copper tests are not low enough to ensure the concentration is safe for inverts.
Good luck.

Adam Obenauf · Feb 29, 2016

Activated carbon is not effective as removing inorganic copper. Cuprisorb can though.

That's actually a better method than an acid bath. Use RO/DI water to let it leach out and run cuprisorb in the filter.

4FordFamily · Feb 29, 2016

Cuprisorb and active carbon have always done it for me. Had no issue adding corals back in the same tank afterward after it tests zero for copper, add fresh cuprisorb and carbon and do a large water change and wait 48 hours and test again. If still zero you're fine, IMO.

Many hobbyists forget that trace elements of copper exist in the reef and in many of our aquariums and we don't know it. IMO this is one of the bigger misconceptions in this hobby. I've successfully removed copper from about a dozen DT on separate occasions and never had any issues with coral or inverts after doing as I describe above.

I'm not contending that leaching doesn't occur, I'm sure it does. I'm saying it has not appeared to be harmful in any way. I've kept clams, sps, and other delicate inverts post-copper.

Randy Holmes-Farley · Feb 29, 2016

Adam Obenauf said:
Activated carbon is not effective as removing inorganic copper. Cuprisorb can though.

That's actually a better method than an acid bath. Use RO/DI water to let it leach out and run cuprisorb in the filter.

Why do you think it better?

I'd use acid to strip the whole surface, and then bleach if there is still organic matter to remove.

Then if I was really worried, I might use Cuprisorb.

FWIW, I don't think kits are going to read low enough to be useful, except if you detect any it is much too much copper.

Adam Obenauf · Feb 29, 2016

Randy Holmes-Farley said:
Why do you think it better?

No dissolution of the rock necessary and more likely to penetrate into the deep pores since you can leave it in there for 48+ hours. Can't exactly do that with acid or there won't be any rock left to save.

Randy Holmes-Farley · Feb 29, 2016

Adam Obenauf said:
No dissolution of the rock necessary and more likely to penetrate into the deep pores since you can leave it in there for 48+ hours. Can't exactly do that with acid or there won't be any rock left to save.

Thanks. That doesn't convince me, but I've not seen any side by side data to prove what is better.

captainsmitty · Mar 1, 2016

What kind of acid for the bath and at what mix levels?
I'm thankful for everyone's input.
Capt. Smitty

Randy Holmes-Farley · Mar 1, 2016

captainsmitty said:
What kind of acid for the bath and at what mix levels?
I'm thankful for everyone's input.
Capt. Smitty

There are numerous threads, but the link below is a fully described method. You can use vinegar (undiluted) or muriatic acid (about 1 part acid diluted into 10 parts fresh water).

http://www.reefedition.com/live-rock-acid-bath/